ZEB1 and neoplasm: However, certain variations from the CSC–EMT marker expression patterns identified in vitro could be noted as well, e.g., differing expression of L1CAM, SOX2, ZEB1, and ZEB2 in the Panc89 Holo- and Paraclone tumors and SOX2 expression in Panc1 Holoclone tumors, indicating the phenotypic switching of CSCs and non-CSCs upon the influence of the distinct tumor microenvironments.